Is there a benefit of low-dose aspirin in assisted reproduction?

The relationship between the change in serum high sensitivity C-reactive protein levels and IVF success

The aim of this study was to assess whether the extent of the change in high sensitivity C-reactive protein (hs-CRP) levels is related with in vitro fertilization (IVF) success. A total of 69 IVF cycles using long luteal GnRH agonist protocol at the IVF unit, were prospectively studied. The serum levels of hs-CRP were measured on the day of initiation of gonadotrophin stimulation and 7 days after embryo transfer. CRP ratio was defined as the levels of CRP on day 7 of transfer/day of initiation of ovarian stimulation. Clinical pregnancy rates were examined. The mean concentrations of hs-CRP were not significantly different on the first day of ovarian stimulation and on day 7 after embryo transfer among pregnant and non-pregnant women. There was a significant rise in hs-CRP levels at 7th day after embryo transfer as compared with the first day of gonadotrophin treatment in both groups (10.58 ± 11.35 versus 3.61 ± 2.86 mg/L for pregnant women and 9.14 ± 11.36 versus 3.24 ± 2.68 mg/L for non-pregnant women, p = 0.001). In addition, the mean CRP ratio was not different between the pregnant and non-pregnant groups. Our data show that serum hs-CRP levels increase during IVF treatment, but the extent of the rise in CRP levels is not a predictive marker of IVF success.

What can the clinician do to improve implantation?

Implantation is a complicated process that requires the orchestration of a series of events involving both the embryo and the endometrium. Even with the transfer of high quality embryos, implantation rates remain relatively low. The growing tendency towards transferring fewer embryos provides further incentives to improve implantation rates. In this article, the various clinical strategies employed to increase the chance of implantation are reviewed. Embryo transfer technique is a critical step in assisted reproductive technology cycles. Recent studies have shown significant improvements in clinical pregnancy rates resulting from careful embryo transfer technique, appropriate catheter type and placing for embryo transfer. Increasingly, adjuvant pharmaceutical therapies are also being applied with the aim of improving embryo implantation. However, the evidence for their efficacy and safety is limited. Recent evidence suggests that adoption of milder ovarian stimulation regimens may provide a more effective clinical approach to improving implantation, since beneficial effects have been shown for both endometrial receptivity and embryo quality.